Note: Descriptions are shown in the official language in which they were submitted.
~13~'3
The present inyention is concerned with certain benzene
carbothioic acid-2~aminoalkylester acid salts useful in combatting
and controlling mucus build-up in an animal exhibiting lung
congestion and compositions for use as mucolytic agents.
This application is divided from applicant's co-pending
application Serial No. 333,424 filed on August 9, 1979 which is
directed to certain novel compounds selected from a compound
selected from substituted benzene and thiophenecarbothioic acid,
2-aminoalkyl ester acid salts having the formula:
ro
¦R-C-S(CH2)nNH3 ¦ X
~herein R is 2-thiophene, benzene substituted by one to three
radicals which may be the same or different, selected from halogen,
lower alkyl, lower alkoxy, carboxy or trifluoromethyl, X is
chlorine or bromine radical, and n is 2 or 3, these novel compounds
also having been found ~o exhibit mucolytic activity.
The prior art discloses synthesis of benzene carbothioic
acid-2-aminoethylester hydrochloride, W. O. Foye et al, J. Pharm.
Sci. 51 (2), 168-~1 (1962) but there is no disclosure of mucolytic
activity. Substitution on benzene has not been disclosed. The
prior art discloses certain mucolytic agents such as N-acetyl-
cysteine having a free sulfhydryl group, which group compounds of
the present invention do not have. A. L. Sheffner, Ann. N.Y.
Acad. Sci. 106, 298-310 (1963) established the use of gastric
mucin mucoprotein as a test media in development of N-acetyl-L-
cysteine as a mucolytic agent in the treatment of lung disease.
According to the present invention there is provided
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a pharmaceutical compos~tion useful as a mucolytic agent in an
animal body sufferin~ from lung congestion which comprises a
pharmaceutically active amount of a compound of the formula
l _ _
IR-C-S(CH2)nNH3
wherein; R is benzene, X is chlorine or bromine radical, and
n is 2 or 3, which is in admixture with a pharmaceutically accept-
able diluent or carrier.
The compositions have mucolytic activity and are useful
in dissolving and diluting mucus in warm-blooded animals exhibiting
or suffering from lung congestion.
The present invention, together with those novel com-
pounds of the aforementioned application Serial No. 333,424, will
now be further described.
The novel and known compounds described hereinafter and
represented by the Formula I
~- 0
+I
( 2)n 3 ~
Formula I
wherein; R is 2-thiophene, benzene or benzene substituted by one
to three radicals which are selected from halogen lower-alkyl,
lower-alkoxy, carboxy or trifluoromethyl and may be the same or
~0 different and in various positions relative to one another on the
ring. X is a chlorine or bromine radical and n is 2 or 3, have
been shown by a modification of the method of S. J. Carne et al,
~:~l3~
J. Phys. 242, 116 (1~74) as described he~einbelow ~hown to have
mucolytic activity in antmals.
Compounds for which mucolytic activity was found to be of
the same order of magnitude as N-acetyl-L-cysteine on rat stomach
mucus are the preferred compounds ~hich are:
1) Benzenecarbothioic acid, 2-aminoethyl ester, monohydro-
chloride,
2) 4-Chlorobenzenecarbothioic acid, 2-aminoethyl ester,
monohydrochloride,
3) 4-Methylbenzenecarbothioic acid, 2-aminoethyl ester,
monohydrochloride,
4) 4-Methoxybenzenecarbothioic acid, 2-aminoethyl ester,
monohydrochloride,
5) 2-Thiophenecarbothioic acid, 2-aminoethyl ester, monohydro-
chloride.
The method used to establish mucolytic activity in the
compounds o formula I is as follows.
Female Sprague-Dawley (Charles River Labs) 120-180 g
rats are fasted 16 hours on wire, housed two animals per cage.
~0 To minimize coprophogia, the lights are left on during the fast.
Two cc of water are given orally to each rat to minimi~e internal
debris. Thirty minutes later the rats are sacrificed by
cervical dislocation. The stomachs are removed, trimmed of
excess tissue and the epithelial portion discarded. The glandular
portion is cut sufficiently along the greater and lesser curvature
to cause eversion of the stomach be~ore placing it in the drug
solution. Stomachs with a fecal odor or containing visible fecal
.
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73
matter a~e d~sc~rdede ~to~achs are ~lace~ n lQ cc of solution
(water or 5Q% PE~ 300~H2a dependin~ on solu~lity) containing 2.5
mg test compound/ml for 40 minutes. After drug treatment the
stomachs are placed in 10 cc Alcian blue solution (Solution 1)
for 90 minutes where the dye complexes with the stomach mucus.
After two successive lO~minute washes in 10 cc of 0.25 M. sucrose
solution (Solution 2), the stomachs are placed in 10 cc 0.5 MgC12
solution (Solution 3) for one hour to remove the complexed dye.
The MgC12 supernatant is shaken with 10 cc diethyl ether in a 60
cc separatory ~unnel to remove lipids. The aqueous phase is
drained into a Spectronic 20 tube and the percent transmission
is read at 605 m,u in a Spectronic 20 spectrophotometer. The per-
cent transmission is converted to ~g/ml of Alcian Blue from a
standard curve. (P. Whiteman, Biochem. J. 131, 351-57 (1973).
Each drug or drug vehicle (control) is tested on three stomachs.
Mean differences between treated and control values are expressed
as percentages.
Solution l-Alcian Blue, 0.05% w/v (1 liter)
54.8 g. sucrose (0.15 M)
6.8 g. sodium acetate
900 cc. deionized water
~0 Dissolve with a magnetic stirrer and adjust to pH 5.8. Add 500 mg.
Alcian Blue 8 GN (Matheson Coleman & Bell # 8E13). Fill to one
liter in a volumetric flask. Refrigerate. Use only for one week.
Solu*ion 2-Sucrose, 0.25 M (1 liter)
Add 85.6 g of sucrose to one liter volumetric flask, Fill to
volume with deionized water. Use only for one week.
~.~3~
Solution 3-Magnesium Chloride, 0.5 M (1 liter)
Add 101.7 g Mg C12.6H20 A.C.S. to a one liter volumetric flask.
Fill to volume with deionized water.
It is ~herefore an object of the present invention to
provide certain novel carbothioic acid, 2-aminoalkylester acid
salts having mucolytic activity in a warm-blooded animal.
A further object is to provide a method of using benzene
and substituted benzene and 2-thiophene carbothioic acid-2-
aminoalkylester acid salts as mucolytic agents to combat mucus
build-up in a warm-blooded animal suffering from lung congestion.
A still further object is to provide pharmaceutical
compositions containing the compounds useful for controlling
congestion due to mucus in a warm-blooded animal body.
Additional objects and advantages of the present in-
vention will be apparent to one skilled in the art and still
others will become apparent from the following description of
the best mode of carrying out the present invention and from the
appended claims.
In the definition of the symbols and in Formula I given
above, and where they appear elsewhere throughout the claims and
specification hereof, the terms have the following significance.
"Benzene substituted by one to 3 radicals" as used herein
shall mean a phenyl radical which is substituted by one to 3 radi-
cals selected from the group as hereinabove defined under the de-
finition of R and these substituents can be in various available
positions of the phenyl nucleus and when more thanoneisubstituent is
present,may be the same or di~ferent and may be in various position
combinations relative to each other. The lower-alkyl and lower-
alkoxy substituents each have preferably from one to four carbon
atoms which can be arranged as straight or branched chains.
Examples of the preferred substituents are methyl, ethyl, propyl,
butyl, fluoro, bromo, chloro, iodo, methoxy, ethoxy, butoxy,
carboxy and trifluoromethyl radicals.
METHOD OF PREPARATION
The benzene and substituted benzene and thiophenecarbo-
thioic acid, 2-aminoalkylester acid salts are prepared by
procedures known for preparing the benzene derivatives as
represented by the following equation:
o
R-C-X + HS(CH2)nNH2-HX~ ~ +
1-
¦R-C-S (CH2) nNH3 ¦ X
wherein R, n and X are as defined hereinabove.
Generally, the reactants are mixed and heated over a
steam jet until a mass of cyrstals are formed. The mass of
cyrstals is then broken up, triturated with ligroine and
recrystallized from anhydrous ethanol.
The following examples of preparation of compounds are
only intended to illustrate the present invention and are not to
be construed as limiti~g the invention in any respect.
Example 1
Benzenecarbothioic Acid, 2-Aminoethylester, Mono-
~.
A mixture of benzoyl chloride, 15 ml. (ca 0.13 mole) and
~3~
2-aminoethanethiol hydrochloride, 4.54 g. (0.04 mole) was heated
(protected from moisture) over a steam jet for 2 hours. Slight
cooling produced a mass of crystals. After trituration with
60-110C. ligroine filtration and drying, the crystals melted at
177-180C. Se~eral recrystallizations from anhydrous ethanol
produced a colorless solid which melted at 178.5-179.5C. Nuclear
Magnetic Resonance (NMR), Mass Spectrophotometer (MS) and Infra
Red (I~) analyses all supported structure of the title compound
in accordance with Formula I. Yield was 5.1 g. (59.1~).
Analysis: Calculated for C8C12ClNOS: C,49.65; H,5.55; N, 6.43
Found : C,49.58; Ht5.59; N, 6.49
Example 2
4-Chlorobenzenecarbothioic Acid, 2-Aminoethyl Ester,
Monohydrochloride.
A mixture of freshly distilled p-chlorobenzoyl chloride,
60 ml. (0.47 mole) and 2-aminoethanethiol hydrochloride,
18.18 g. (0.16 mole) was heated (protected from moisture) over
a steam jet for 2 hours. A solid crystalline mass formed as the
reaction went to completion. After careful trituration with
~0 warm 60-110C. ligroine, crystals were separated by filtration
while washing with ligroine. After two recrystallizations from
anhydrous ethanol, the product, 39.0 g. (96.5%), melted at
208-209.5C. NMR, MS and IR analyses all supported structure of
the title compound in accordance with Formula I.
Analysis: Calculated for C~HllC12SNO: C,42.87i H,4.40; N,5.55
Found : C,42.79; H,4.43; N,5.59
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Example 3
4-Methylbenzenecarbothioic Acid, 2-Aminoethyl Ester,
Monohydrochloride.
A mixture o freshly distilled p-toluoyl chloride, b.p.
122C./32 mm, Hg., 30 ml. (ca 0.18 moles) and 2-aminoethanethiol
hydrochloride, 9.68 g. (0.085 moles) was heated (protected from
moisture) over a steam jet for 2.25 hours. A solid crystalline
mass formed on completion of the reaction. The mass was crushed
and careully triturated with warm 60-110C. ligroine and crystals
were separated by iltration and washed with warm ligroine. After
two recrystallizations from anhydrous ethanol, the product, 19.07
g. (97%), melted at 206.5-208C. NMR, MS and IR analyses all
supported the structure of the title compound in accordance with
Formula I.
Analysis: Calculated for CloH14NOClS: C,51.83; H,6.09; N,6.04
Found : C,51.57; H,6.06; N.6.11
Example 4
4-~ethoxybenzenecarbothioic Acid, 2-Aminoethyl Ester,
Monohydrochloride.
~0 A mixture of p-anisoyl chloride, 23 ml. (ca 0.135 mole)
and 2-aminoethanethiol hydrochloride, 7.4 g. (0.065 mole) was
heated (protected ~rom moisture) over a steam jet for about 2 hours.
The resultant crystalline mass was crushed and carefully triturated
with warm 60-110C. ligroine and crystals were separated by
filtration and washed with warm ligroine. Ater two recrystal-
lizations from anhydrous ethanol, the productl 14.6 g. (90.6%)
-melted at 191.5~1q3~C. NMR, MS and IR analyses all supported the
73
s~ructure of the title compound in accordance with Formula I.
Analysis: Calculated for C10~14ClN02S: C,48.48; H,5.69; N,5.65
Found : C,48.42; H,5.73; N,5.66
Example_5
When in the procedure of Example 1, benzoyl chloride is
replaced by equal molar amounts of
3,4,5-trimethoxybenzoyl chloride,
4-fluorobenzoyl chloride,
3-trifluoromethylbenzoyl chloride,
3,4-dichlorobenzoyl chloride,
3,4-dimethylbenzoyl chloride, and
4-carboxybenzoyl chloride
there are obtained
3,4,5-trimethoxybenzenecarbothioic acid, 2-aminoethyl
ester hydrochloride,
4-flurorobenzenecarbothioic acid, 2-aminoethyl ester
hydrochloride,
3-trifluoromethylbenzenecarbothioic acid, 2-aminoethyl
ester hydrochloride,
~0 3,4-dichlorobenzenecarbothioic acid, 2-aminoethyl ester
hydrochloride,
3,4-dimethylbenzenecarbothioic acid, 2-aminoethyl ester
hydrochloride, and
4-carboxybenzenecarbothioic acid, 2-aminoethyl ester
hydrochloride.
Example~6
~ hen in the procedure of Example 1, 2-aminoethanethiol
~.~,3~f~7~3
hydrochloride is replaced by equal molar amounts of 3-amino-
propanethiol hydrochloride, there is obtained
benzenecarbothioic acid-3-aminopropylester hydrochloride.
Example 7
When in the procedure of Example 1, 2-aminoethanethiol
h~drochloride is replaced by equal molar amounts of 3~amino-
propanethiol hydrochloride and benzoyl chloride is replaced by
p-chlorobenzoyl chloride,
p-toluoyl chloride, or
p-anisoyl chloride
there are obtained
4-chlorobenzenecarbothioic acid, 3-aminopropyl ester
hydrochloride,
4-methylbenzenecarbothioic acid, 3-aminopropyl ester
hydrochloride, and
4-methoxybenzenecarbothioic acid, 3-aminopropyl ester
hydrochloride.
Example 8
2-Thiophenecarbothioic Acid, 2-Aminoethyl Ester,
2a Hydrochloride.
A mixture of freshly distilled 2-thiophenecarbonyl
chloride, 15.8 g. (0.108 mole) and 2-aminoethanethiol hydrochloride
11.3 g. (0.1 mole) was heated (protected from mois~ure) over a
steam jet for 6 hours. The resulting solid crystalline mass was
crushed and triturated with warm 60-110C. ligroine and filtered
to collect the crystals. After two recrystallizations from
anh~drous ethanol, the product, 8.41 g. (75.5%) melted at
- 10 -
73
195-196.5C. NMR, MS and IR all supported the structure of the
title compound in accordance with Formula I.
Analysis: Calculated for C7HloClNOS2: C,37.58; H,4.51; N,6.26
Found : C,37.68; H,4.50; N,6.30
Example 9
When in the procedure of Example 8, 2-aminoethanethiol
hydrochloride is replaced by equal molar amounts of 3-amino
propanethiol hydrochloride, there is obtained thiophenecarbothioic
acid, 3-aminopropyl ester hydrochloride.
The pharmaceutical compositions of this invention comprise
benzenecarbothioic aoid, 2-aminoethyl ester acid salts in an amount
sufficient to provide efective action against lung congestion in
warm-blooded animal subjects when applied topically as an inhalant.
The compounds of Formula I are administered in an amount
sufficient to induce liquefaction of mucus in the respiratory
tract o warm-blooded animals in need thereo. Intratracheal
administration of the compounds of Formula I is effected by
various inhalation or instillation means such as nose drops, sprays,
aerosols and the like. Another suitable means of administration
~0 is by insufflation of micronized particle or ultra-fine powder
utilizing only the energy of the inspiratory action or by use of
aerosol propellants. Solutions or suspensions having about 0.5 to
5% weight of the mucolytic agent of Formula I are suitable for
application by spraying with an atomizer, nebulizer, aerosol and
the like.
~ t will be readily apparent to those skilled in the
medical art that the correct dosage of a compound to be employed
-- 11 -- ..
7~
with any particular ma~malian subject is determined by the
severity of the condition requiring mucolytic therapy, as well as
the age, sex, weight and general physical condition o the sub~ect.
Individual doses ranging from 5-100 mg. for inhalation by man are
suitable and may be required for the mucolytic effect.
The pharmaceutical compositons may take the form of
dilutions of the micronized compounds in dusts or solutions and
suspensions in liquids suitably dispensed for inhalation as
illustrated following.
A. Powder for Administration via In,haler Device.
4-Chlorobenzenecarbothioic acid, 2-aminoethyl ester
monohydrochloride of Example 2,
micronized 2.5 g.
Lactose powder 2.5 g,
The powders are blended aseptically and filled into
hard gelatin capsules each containing 50 mg. of the mixture.
This is suitable for dispersion into the inspired breath by means
o~ a breath-operated inhaler device containing means for rupture
of the capsule wall prior to dosing.
~0 B. Sterile Solution for Administration via Inhaler Device.
1. Active Ingredients 100 mg.
2. Alcohol 95%, q.s. 1.0 cc.
Dissolve No. 1 and 2 by warming and administer by means
of breath-operated inhaler device.
- 12 -
~3~27~3
C. Aqueous Solution
1. Active Ingredient, Ex. 1, 3 or 5 10 g.
2. Distilled water 90
Total 100 g.
Dissolve 1 in 2 and dilute to dosage forms and administer
by means of inhaler device or aerosol.
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